Dynamometric tool

ABSTRACT

A dynamometric tool uses a four-mandrel press. The press head is provided with a specific press geometry which is predefined by the mandrels. The dynamometric tool produces a tool which can determine the actual force of compression in an easy-to-handle manner. The dynamometric tool also has two levers which are joined together and adapted to the geometry of the press head, and which interact upon a pressure sensor during compression.

This is a National Phase application of PCT Application No.PCT/EP01/10390, filed Sep. 8, 2001, which claims priority from GermanApplication No. 10051010.8, filed Oct. 14, 2000.

Four-mandrel press heads of this type are known. Reference is made here,for example, to Canadian Patent 679,495. One of the advantages of suchpress heads is that a new insert is not required for each geometry of acable shoe or the like that is to be pressed with said press heads. Theforce with which pressing actually takes place is difficult to verify inthe case of such four-mandrel press heads.

With regard to the prior art described above, one technical problem forthe invention is seen as that of providing a dynamometric tool for afour-mandrel press head by means of which the actual pressing force canbe determined in an easy-to-handle manner.

This problem is solved in the first instance and substantially by thesubject-matter of Claim 1, which provides two levers which are joinedtogether and adapted to the pressing geometry of the press head andwhich act on a pressure sensor in the course of pressing. In a preferredconfiguration, the dynamometric tool according to the invention isformed like a gage, as a hand-held device. The two levers of thisdynamometric tool gage are adapted in the region to be associated withthe four-mandrel press head to the pressing geometry predefined by themandrels, with the result that the mandrels act on the dynamometric toolin the course of the test pressing operation in such a way that ameasurement of the actual pressing force is achieved. The pressingforces introduced into the levers are determined by a pressure sensordisposed in the dynamometric tool, which determined value can, forexample, be indicated. Storage of the determined value in thedynamometric tool is also conceivable. In an advantageous way, thedynamometric tool according to the invention is formed as a handymeasuring gage, so that it can be used at any time, i.e. even in situ ona construction site, etc. It is provided in a development of thesubject-matter of the invention that the levers are connected to eachother at one end in a pivoted manner and, on the opposite side, end in afreely projecting manner. The pressure sensor is in this case disposedbetween the two levers interconnected in a pivoted manner, the way inwhich the levers are disposed in relation to each other further beingchosen such that, in the unloaded state, these levers of thedynamometric tool, with the pressure sensor disposed in between, do notrun parallel to each other but diverge. As a result of thisconfiguration, the high forces which are introduced into thedynamometric tool during pressing can be transferred. It is alsoproposed that a receiving geometry for the press mandrels isrespectively formed on the levers. Consequently, each lever is furtheradapted in its receiving geometry to the pressing geometry of twoneighboring mandrels of the four-mandrel press head. In a furtheradvantageous configuration, it is provided that the receiving geometryof each lever is chosen such that the mandrels of the four-mandrel presshead act at an angle of preferably 45° to the plane between the twolevers of the dynamometric tool. It further proves to be particularlyadvantageous that the pressure sensor is disposed at a spacing from thereceiving geometry, with respect to the length of the levers. Forexample, with respect to the length of the levers, it is provided forthe pressure sensor to be disposed between the receiving geometry andthe pivoted connection of the levers. Since the force in thefour-mandrel press head is transmitted in a predetermined ratio, it isproposed in an advantageous development of the subject-matter of theinvention that this transmission is also provided in the dynamometrictool. It is consequently proposed that the ratio of the spacings of thepressure sensor on the one hand and the receiving geometry on the otherhand from the pivoted connection of the levers is chosen such that thepressure sensor indicates the actual pressing force irrespective of theforce transmission dictated by the way in which the mandrels aregeometrically disposed. It is consequently preferred to transmit theforce in the four-mandrel press head with a factor of “root 2”. Acorresponding transmission ratio is reproduced by the dimensions of thelever arms on the one hand and the location of the pressure sensor inrelation to them on the other hand. In addition, the actual drive forcecan then be indicated. The ratio of the spacings of the pressure sensorand the receiving geometry from the pivoted connection of the levers isconsequently likewise chosen as a “root 2” ratio. In an alternativeconfiguration, it may be provided that the receiving geometry isdisposed between the free end region, with which the pressure sensor isalso associated, and the pivot. A ratio of the spacings of the pressuresensor and of the receiving geometry from the pivoted connection of thelevers which is adapted to the force transmission in the four-mandrelpress head is also preferably chosen here. Furthermore, it isalternatively provided that the receiving geometry is disposed midwayalong the levers and that pressure sensors are provided on both sides ofthe receiving geometry.

The invention relates furthermore to a dynamometric tool for afour-mandrel press head, the four-mandrel press head having a pressinggeometry predefined by the mandrels. To develop a dynamometric tool ofthe type in question in an advantageous way, it is proposed that twothrust pieces which are adapted to the pressing geometry and act on apressure sensor in the course of pressing are provided. Thisconfiguration produces a handy dynamometric tool, measurement of theactual pressing force being carried out by placing the dynamometric toolin the press head in such a way that the mandrels of the press head acton the thrust pieces adapted to the pressing geometry. The pressuresensor disposed between these thrust pieces thereby determines thepressing force in an extremely easy way. It proves to be particularlyadvantageous here that a receiving geometry for the press mandrels isformed on each of the thrust pieces, the receiving geometry of the twothrust pieces being joined together and adapted to the pressing geometryof the press head. Finally, it is proposed that the pressure sensor andthe receiving geometries are disposed in the same region of the thrustpieces, with the result that the pressure sensor lies in the pressingplane, i.e. in the plane acted on by the four mandrels of the presshead, in the course of the pressing for measuring purposes.

The invention is explained in more detail below on the basis of theaccompanying drawing, which merely represents several exemplaryembodiments and in which:

FIG. 1 shows a side view toward a dynamometric tool in a firstembodiment;

FIG. 2 shows the section along the line II—II in FIG. 1;

FIG. 3 shows the dynamometric tool of the first embodiment in aperspective exploded representation;

FIG. 4 shows the way in which the dynamometric tool according to theinvention is associated with a four-mandrel press head in a perspectiverepresentation;

FIG. 5 shows a partially sectioned view of the set-up according to FIG.4;

FIG. 6 shows a four-mandrel press head partially in section, with theassociation of the dynamometric tool acted on by the mandrels;

FIG. 7 shows a representation of a detail in section along the lineVII—VII in FIG. 6;

FIG. 8 shows a side view corresponding to FIG. 1, but concerning asecond embodiment of the dynamometric tool;

FIG. 9 shows the section along the line IX—IX in FIG. 8;

FIG. 10 shows a further embodiment of the dynamometric tool;

FIG. 11 shows the section along the line XI—XI in FIG. 10;

FIG. 12 shows the dynamometric tool according to FIG. 10 in aperspective individual representation;

FIG. 13 shows a further embodiment of the dynamometric tool;

FIG. 14 shows the section along the line XIV—XIV in FIG. 13;

FIG. 15 shows the perspective representation of the dynamometric toolaccording to FIG. 13;

FIG. 16 shows the dynamometric tool in a further embodiment;

FIG. 17 shows the section along the line XVII—XVII in FIG. 16;

FIG. 18 shows the perspective representation of the dynamometric toolaccording to FIG. 16.

Represented and described, in the first instance with reference to FIG.1, is a dynamometric tool 1 for a four-mandrel press head 2—asrepresented in FIG. 4. The first exemplary embodiment of thedynamometric tool 1, represented in FIGS. 1 to 7, substantiallycomprises two levers 4, 5, which are disposed parallel to each other,are connected to each other by means of a pivot point 3 and betweenwhich a pressure sensor 6 is disposed.

The set-up is further chosen such that, in a basic position, i.e. in theunloaded state, the levers 4 and 5 do not run parallel to each other butdiverge from each other.

The pressure sensor 6 lies in receptacles 7, 8 extending from themutually facing surfaces of the levers 4 and 5.

The pivot 3, formed at the one, free ends of the levers 4, 5, is formedby a pivot pin 9, which passes through the levers 4 and 5 and iscaptured at the ends on both sides by means of securing rings 10.

The freely projecting ends, lying opposite the pivot 3, of the levers 4and 5 are formed in such a way that they are adapted to the pressinggeometry predefined by the mandrels 11 of the press head 2, andaccordingly have in each case a receiving geometry 12 for the pressmandrels 11.

Each receiving geometry 12 is accordingly formed by twocross-sectionally triangular depressions 13, the way in which thesedepressions 13 are associated with each other being chosen such that, ina cross-section according to FIG. 2, the axes of symmetry x form anangle alpha of 90°, each axis of symmetry x being aligned furthermore atan angle beta of 45° in relation to the parting surface 14 of therespective lever, facing the opposite lever.

As can be seen in FIG. 2, the receiving geometry 12 of the freelyprojecting ends of lever 4 and lever 5 are disposed symmetrically inrelation to the parting plane formed between the levers 4 and 5.

The pressure sensor 6 is disposed—with respect to the length of thelevers 4, 5—at a spacing a from the receiving geometries 12. So, in theexemplary embodiment represented, a ratio of the spacings of thepressure sensor 6 on the one hand—length 11—and the receiving geometry12 on the other hand—length 12—from the pivoted connection 3 of thelevers 4, 5 of about 1:1.415, i.e. 1:“root 2”, is chosen. So, forexample, the length 11 between the pivot 3 and the pressure sensor 6 maybe 100 mm and the length 12 between the pivot 3 and the receivinggeometry 12 may be 141.5 mm.

The two levers 4 and 5 are secured against swinging open about the pivot3 by means of a knurled screw 15, allowing a pivoting movement of thelevers 4, 5 in the pressing direction.

The dynamometric tool 1 according to the invention is formed like agage, in the form of a hand-held device, and, for measuring the pressingforce in a press head 2, is inserted into the press mouth 16 of thepress head 2 in such a way that the receiving geometries 12 or theshaped depressions 13 of the dynamometric tool 1 are aligned such thatthey are associated with the four press mandrels 11 (cf. FIGS. 4 and 5).

The press head 2 is, for example, associated with a hydraulic device(not represented), which, on actuation, acts on the press mandrels 11with a pressing force F. The four press mandrels are distributed atequal angles in a cross-section according to FIG. 6, and accordinglyform in each case an angle of 90° with respect to one another. As aresult of the transmission ratios, each press mandrel 11 acts with halfthe pressing force F/2 on the item to be pressed or, as represented, onthe dynamometric tool 1.

The fact that the chosen way in which the receiving geometries 12 aredisposed in the region of the levers 4, 5 has the effect that half thepressing forces F/2 act at an angle beta of 45°, with respect to theparting surfaces 14 of the levers 4, 5, produces a force resultant FRwhich acts perpendicular to the parting surface 14 and is greater thanhalf the pressing force F/2 by a factor of “root 2”.

This factor of “root 2” is nullified by the chosen ratio of the lengths11 and 12, with the result that the actual pressing force F in theregion of the pressure sensor 6 is determined. This determined value canbe indicated or else stored.

The configuration according to the invention provides a dynamometrictool 1 which, as a gage-like hand-held device, determines the actualpressing force F of a four-mandrel press head 2 in an extremely easyway.

Represented in FIGS. 8 and 9 is a further exemplary embodiment of adynamometric tool 1 according to the invention. Here, too, two levers 4,5 are connected to each other by means of a pivot 3, having a pivot pin9. By contrast with the previously described first exemplary embodiment,however, provided here is a set-up in which the receiving geometries 12are formed between the free end region, in which the pressure sensor 6is disposed, and the pivot 3. In the case of this embodiment, too, aratio of the spacings of the pressure sensor 6 on the one hand and ofthe receiving geometry 12 on the other hand from the joint 3 is chosensuch that, in a way corresponding to the first exemplary embodiment, thepressure sensor 6 indicates the actual pressing force F irrespective ofthe force transmission dictated by the way in which the press mandrels11 are geometrically disposed. So, here a ratio of the lengths 11between the pressure sensor 6 and the pivot 3 and the length 12 betweenthe receiving geometry 12 and the pivot 3 of “root 2”:1 is provided, toneutralize the “root 2” factor of the force resultant FR acting on thelevers 4, 5.

FIGS. 10 to 12 show a further exemplary embodiment. Here, the receivinggeometry 12 and the pressure sensor 6 are disposed in the same way as inthe previously described exemplary embodiment according to FIGS. 8 and9. Here, too, the spacing ratios 11 to 12 are chosen as “root 2”:1. Inthis exemplary embodiment, a roller bearing 17 is chosen as the pivot 3.

A further alternative configuration of the dynamometric tool 1 accordingto the invention is represented in FIGS. 13 to 15. Here, the receivinggeometry 12 or the shaped depressions 13 are formed midway along thelevers 4, 5. Pressure sensors 6 are provided on both sides of thesereceiving geometries 12.

As a further alternative, according to the exemplary embodiment in FIGS.16 to 18 it is possible to choose a set-up providing two thrust pieces18 which are adapted to the pressing geometry of the press mandrels 11and act on a pressure sensor 6 disposed between these thrust pieces 18in the course of pressing by the press head 2. Here, too, in a waycorresponding to the previously described exemplary embodiments, thethrust pieces 18 have receiving geometries 12 for the press mandrels 11that are joined together and adapted to the pressing geometry. Thepressure sensor 6 and these receiving geometries 12 are disposed in thesame region, preferably in the central region of the thrust pieces 18.

All disclosed features are (in themselves) pertinent to the invention.The disclosure content of the associated/attached priority documents(copy of the prior patent application) is also hereby incorporated infull in the disclosure of the application, including for the purpose ofincorporating features of these documents in claims of the presentapplication.

1. A dynamometric tool for a four-mandrel press head, the four-mandrelpress head having a pressing geometry predefined by mandrels, saiddynamometric tool configured to be placed in the four-mandrel press headsuch that the mandrels of the four-mandrel press head act on saiddynamometric tool, said dynamometric tool comprising two levers whichare joined together and adapted to the pressing geometry of thefour-mandrel press head, said two levers configured to act on a pressuresensor in order to sense a pressing force of said two levers in thecourse of pressing.
 2. The dynamometric tool as defined in claim 1,wherein the two levers are connected to each other at one end at a pivotpoint and, on the opposite side, end in a freely projecting manner todefine a free end region of the two levers.
 3. The dynamometric tool asdefined in any preceding claim, wherein a receiving geometry for themandrels is respectively formed on the two levers.
 4. The dynamometrictool as defined in claim 3, wherein the pressure sensor is disposed at aspacing from the receiving geometry, with respect to a length of the twolevers.
 5. The dynamometric tool as defined in claim 4, wherein a ratioof a spacing from the pressure sensor to the pivot point and a spacingfrom the receiving geometry to the pivot point is chosen such that thepressure sensor indicates an actual pressing force irrespective of aforce transmission dictated by the way in which the mandrels aregeometrically disposed.
 6. The dynamometric tool as defined in claim 3,wherein the receiving geometry is associated with the free end region,while the pressure sensor is disposed in an associated manner betweenthe pivot point and the receiving geometry.
 7. The dynamometric tool asdefined in claim 3, wherein the receiving geometry is disposed betweenthe free end region, with which the pressure sensor is also associated,and the pivot point.
 8. The dynamometric tool as defined in claim 3,wherein the receiving geometry is arranged midway along the two leversand pressure sensors are provided on both sides of the receivinggeometry.
 9. A dynamometric tool for a four-mandrel press head, thefour-mandrel press head having a pressing geometry defined by mandrels,said dynamometric tool configured to be placed in the four-mandrel presshead such that the mandrels of the four-mandrel press head act on saiddynamometric tool, said dynamometric tool comprising two thrust pieceswhich are adapted to the pressing geometry and are configured to act ona pressure sensor in order to sense a pressing force of said two thrustpieces in the course of pressing.
 10. The dynamometric tool as definedin claim 9, wherein a receiving geometry for the mandrels isrespectively formed on the thrust pieces.
 11. The dynamometric toolaccording to claim 9 or 10, wherein the pressure sensor and thereceiving geometries are disposed in the same region of the thrustpieces.